Apparatus for abrasive finishing of articles by vibratory action



June 29, 1965 J, RAMPE APPARATUS FUR ABRASIVE FINISHING OF ARTICLES BY VIBRATORY ACTION 3 Sheets-Sheet 1 Filed April 17, 1962 INVENTOR. w JOHN E PAMPE- L Bowowlljm f/Mam owl/W ATTORNEYS.

June 29, 1965 J. F. RAMPE 3,191,347

APPARATUS FOR ABRASIVE FINISHING OF ARTICLES BY VIBRATORY ACTION Filed April 17, 1962 s Sheets-Sheet 2 C 9. a 1?: INVENTOR. 2 E 5 6 JOHN F. QAMPE- By BM, 5%, Hm MW ATTORNEYS.

June 29, 1965 J. F. RAMPE APPARATUS FOR ABRASIVE FINISHING 0F ARTICLES BY vmmom ACTION 3 Sheets-Sheet 3 Filed April 17, 1962 97 INVENTOR. JOHN F. PAM/ 5- FEOM BLEED VALVE:

PRESSURE REGULATOR ATTORNEYS:

3,191,347 APPARATUS FUR ABRASIVE FINKSHING F ARTICLES BY VIBRATORY ACTION John F. Rampe, 3417 Fairfax Road, Cleveland Heights, Ohio Filed Apr. 17, 1962, Ser. No. 188,128

15 Claims. (Cl. 51-163) This invention relates to the art of finishing articles by abrasion, more particularly to finishing by cyclic motion of a mass comprising the articles being finished or such articles and an abrasive medium in intimate association.

In vibratory finishers the articles to be finished such as moldings and castings are placed in a receptacle usually with an abrasive medium such as aluminum oxide, steel shot, granite and other stone particles, with or without a liquid vehicle, and the receptacle is vibrated or moved at high speed in an orbital path of small magnitude. The conventional finisher has a carriage, machine frame and supporting structure which are subjected to high stresses and force reversals. As a result the machine frames are heavy and costly, special foundations and machine bases are required and the operation of the conventional finisher produces vibrations in the building in which it is used with attendant annoyance and discomfort to workers and occupants, lowering their efficiency and productiveness; there is considerable cost and difiiculty with maintenance of bearings. Moreover, the energy which is consumed in the shaking of the machine frame, its foundation and the building in which it is mounted, is lost to the finishing process which thus operates at low efficiency. As a result, vibratory finishers heretofore available have not been completely satisfactory.

It is, therefore, one of the principle objects of the present invention to provide a finisher of the type referred to wherein the receptacle or tub for the mass of articles to be finished and the finishing media is mounted in a frame for movement in a predetermined positive orbital path relative to the frame with the weight of the receptacle and its contents yieldingly supported in the frame in such a way as substantially to relieve the driving mechanism of static load. More particularly, this aspect of the invention contemplates an arrangement wherein the receptacle for the mass to be vibrated is shaft mounted in the machine frame with an eccentric connection that imparts the positive orbital movement to the receptacle and wherein means having connection withthe receptacle other than through the shaft imparts a vertical force component to the receptacle substantially equivalent to the weight of the receptacle and its load. In a machine embodying a specialized version of the invention the vertical force component is supplied by a resilient unitary pneumatic device adapted to be inflated to different air pressures so as to vary the force on the receptacle in balancing the weight of the load. 7

Another object of the invention is to provide a vibratory finisher of the orbital type in which the receptacle for the mass to be vibrated comprises a carrier mounted in the machine frame for orbital movement and in combination a tub nested in the carrier in fixml relation, the tub being adapted to be easily removed from and replaced into the carrier in loading and unloading and in changing tubs,

Another object is to provide, in a finisher of the orbital type, a carrier-frame combination in which a tall carrier is interconnected adjacent its lower extremity with the frame by means for an eccetnric shaft and is pin connected to the frame at a vertically remote point to minimize stresses in the pin 'joint during operation. In a further refinement of this aspect of the invention, the work load mass and the center of gravity of the total orbiting mass are located closely adjacent the eccentric shaft to further United States Patent 0 minimize stresses at the pin joint and to achieve substan- V tially circular orbital motion of the work mass.

Another object is to provide a vibratory finisher of relatively simple construction and few parts which can be easily and quickly built at small cost, which occupies but little fioor space, can be operated by unskilled persons to produce superior results faster and more econo1ni cally than heretofore.

Other objects and advantages pertain to certain novel features of construction, combinations and arrangements of parts and process steps as set forth in the following detailed description of a vibratory finisher which represents the best known means of practicing the invention. This description is made in connection with the accompanying drawings, forming part of the specification, wherein like parts are throughout indicated by the same numerals of reference.

In the drawings:

FIGURE 1 i a front perspective of the finisher;

FIG. 2 is a front elevational view of the finisher of FIG. 1, enlarged relative to the latter;

FIG. 3 is an elevational view of the right side of the finisher, with parts broken away, this view being drawn to the same scale as FIG. 2;

FIG. 4 is a fragmentary elevational view of the left side .of the finisher, with parts broken away and removed and partly in section, this view being enlarged with respect to the preceding figures;

FIG. 5 is a horizontal sectional view through the finisher, taken substantially in the broken plane represented by the line 55 of FIG. 4; FIG. 6 is a fragmentary sectional detail taken substantially in the plane represented by the line 66 of FIG. 5 and enlarged relative thereto, this view showing the relationship between the eccentric drive shaft and the eccentric balancing weight;

FIG, 7 is a perspective view of the receptacle or tub which receives the mass of articles to be finished and the finishing medium; and

FIG. 8 is a diagrammatic view of the right side showing the relationships between various centers of gravity, the adjustable supporting air spring, the eccentric driving means and the stabilizing connection between the carrier and the frame structure.

The present vibratory finisher or abrading machine comprises a frame structure 1 which supports the several other components including a carrier 2, a tub or receptacle 3, a drive motor 4- and a control box 5. The frame structure may be made up of castings or, as shown, may comprise welded together rolled steel tubes angle sections and similar elements; it includes a pair of spaced generally parallel right and left side members having relatively short front legs 6, 7, respectively, relatively tall rear legs 8, 9, respectively, and intermediate legs 10, 13, respectively. The legs are all bottomed on and fast to base members 11, 12 which are conveniently made of rolled steel angle sections, the right legs 6, 8 and 10 resting on the horizontal flange of base member 11 and the left legs 7, 9 and 13 resting on the horizontal flange of base member 12.

The machine is installed for use by bolting the base members 11, 12 to a suitable foundation such as a concreate slab.

A horizontal top rail 14 connects the upper end of the short right front leg 6 to an intermediate point of the tall right rear leg 8; a corresponding top rail 15 connects the upper end of the short left front leg to an intermediate point of the tall left rear leg 9. Suitable cross ties hold the side members in the desired spaced parallel relationship; bottom ties 16, 17 extend between the lower ends of the front and rear legs, respectively; an intermediate cross tie 18 connects the rear legs at the level of the top rails 14, 15, and a top channel-shaped cross tie 19 connects the upper ends of the tall rear legs 8, 9. Suitable diagonal braces 28, 29 which comprise steel angle section members are welded in place between the front and intermediate legs, the brace 28 being part of the right side, the brace 29 being part of the left side of the frame structure.

The carrier 2 comprises a pair of spaced parallel side panels 21, 22 of suitable sheet metal such as cold rolled steel. These panels are generally triangular in shape, being formed with integral flanges 23, 24 along their front or hypotenuse and rear or long leg edges, respectively. The lower portions of the side panels are joined integrally or as by welding to front, bottom and rear connecting walls 25, 26 and 27, respectively, to provide a pocket for receiving the tub or receptacle 3. The rear wall 27 is spaced forwardly from the rear edges 24 of the side panels, providing in the carrier a rear recess or open chamber 40 through which extends an actuating shaft 30 carrying an eccentric balancing weight 31. The top of the chamber or recess is closed by a connecting wall 32 which extends from the rear edges of the side panels forwardly to the upper edge of the rear wall 27 to which such connecting top wall is joined. Suitable metal stiffeners, not shown, are welded to the panels of the carrier and in its corner angles to impart adequate strength and rigidity to withstand shaking and vibration which occurs in operation.

The carrier front wall 25 is relatively low so that the tub 3 can be easily lifted into and out of the pocket 20. A clamping bar 33 is disposed across the front of the pocket and spaced above the top edge of the wall 25. This bar is held in place by a pair of threaded rods 34. These rods at their distal ends are anchored to lugs 35 on the side panels 21, 22, there being two lugs on the outside of each panel with the corresponding one of the rods 34 being received between the lugs. Bars 36, one on the distal endof each of the rods 34 are received behind corresponding pairs of the lugs 35, in recessed portions of the latter. ceive the rods 34 with heads or nuts threaded on the rods engaging and stopping against the bars. The proximate or forward ends of the threaded rods 34 are received through holes drilled in the clamping bar 33 and accommodate nuts 38 which allow for adjustment of the clamping bar to clear the rim of the particular tub or receptacle 3 being used. The clamping bar has threaded therethrough an adjusting hand screw 41 on the inner end of which may be a suitable pad received between the side panels of the carrier and rotatable on the screw so as to be disposed and tightened with strong force snuggly against the tub or a cross bar of the latter in clamping relation or, as shown, the inner end of the screw 41may bear directly against one of the cross bars 42 of the tub.

The sheet metal tub 3 provides an enclosed compartment into which are charged the articles to be finished by abrasive action and is designed to fit into the pocket 26 of the carrier for easy removal and replacement with minimum clearance between spaced parallel circular end walls 45, 46 of the tub and the side panels 21, 22 of the carrier. Extending between and connected to the tub end walls 45, 46 are flat connecting walls 47. These connecting walls are at obtuse angles to one another and are arranged to define an equilateral polygonal figure. Preferably, as shown, there are five of the connecting walls 47, equal to one another in length and width and arranged about and to define five sides of a hexagonal chamber, the open sixth side constituting a charging opening 44 provided with a removable closure panel 48. Along its opposite edges the closure panel 48 is formed with angularly disposed lips or flanges 49 which, overlap the edges ofthe two connecting walls 47 that are adjacent the opening 44. A hand screw 51 is threaded through oneof the cross bar reinforcements 42, which is centered over the opening 44, the hand screw being adapted to be engaged directly and normally against the center of the These cross bars are drilledto reripheries of the end Walls.

closure 48 clampingly to retain the latter in place across the access opening of the tub. There are six of the cross bars 42, corresponding to the six sides of the hexagonally shaped finishing chamber as defined by the five connecting walls 47 and the closure 48. The cross bars 42 are all located on a common circle within the profile of the circular end Walls 45, 46, the bars being equiangularly spaced about the axis of the tub. To reinforce the edges of the end walls 45, 46 the latter are provided with inturned, axially directed circular flanges 55, 56. These flanges comprise steel bands welded to the circular p,-

The cross bars 42 are located radially outward from and in spaced relation to the connecting walls 47 and radially inwardly from the reinforcing rings 55, 56 of the end walls. Thus the cross bars constitute convenient handle means to be grasped in manipulating the tub to lift it into and out of the carrier'for loading and unloading.

The carrier 2 is disposed between the right and left side members of the frame structure with intervening clearances 57 to allow for relative movement and vibration that occurs in operation, as will appear. The weight of the carrier, tub or receptacle 2 and the work load contents M of the latter, considered as a unit, is carried by resilient means in the form of a pneumatic spring 60 substantially centered under the tub. The side panels 21, 22 of the carrier 2 are connected by an intermediate cross brace 61 and the upper end of the carrier, distal from the actuating shaft 30, includes a channel-shaped cross member 63. The ends of the brace 61 and the cross member 63 abut and are welded to the inside surfaces of the carrier side panels 21, 22. j 7

Right and left panels 67, 68, respectively, and a rear panel 76 are secured as by welding to the outsides of the frame members and are formed with suitable openings to accommodate the various shafts and rods. Against the central portion of the rear face of the cross member 63 is disposed a hearing or pillow block 64 secured in place as by bolts; a similar block 65 is likewise secured to the top channel-shaped'cross member 19 of the frame structure 1. The blocks 64, 65 are opposite and confront one another and are connected by stabilizing link means 62 comprising a pair of spaced links one on each side of the bearing blocks and pivotallyconnected to the latter by pins 66, 67. The axes of the link pins 66, 67, spaced horizontally a distance e of 4 inches which is very short relative to the carrier height, are parallel to one another and to the shaft 30 permitting limited oscillatory movement of the upper end of the carrier over an arcuate path centered on the axis of the anchorage pin 67 and in a plane normal to the axes of the pins and the shaft 30. The piercing points of the pin axes in such plane constitute interconnecting points of the stabilizing link 62 with the carrier and the frame structure. The upper end of the carrier is thus tied to a point of the frame structure represented by the axis of the pin 6'7. The horizontal actuating shaft 30, substantially vertically below the frame structure anchorage point represented by the pin 67, is located in the bottom corner angle of the carrier 2 defined by the rear flanges 24 and the bottom plate 26. Thus the shaft 30 operatively connects the lower end of the carrier to the frame structure for relative orbital movement and the link means 62 connects and stabilizes the upper end of the carrier to the frame structure. A central portion 71 of the shaft 30 is journaled in suitable self-aligning bearing assemblies 72, 73 such as known in the trade as ball bearing flanged cartridge blocks. These assemblies are received through aligned circular openings in the carrier side panels 21, 22, respectively, and their flanges are suitably secured to the panels as by bolts, the carrier panels desirably being suitably reinforced. Beyond or outside the carrier bearing assemblies 72, 73, the shaft 30 is formed with reduced diameter end portions 74, 75 which are received through bearing assemblies 76, 78 similar to the bearing assemblies 72, 73 and suitably supported in the side members of the frame structure. For example, rolled steel channel members 78, 79 may be set upright, channel sides facing out and welded in place, the channel 78 between the frame uprights 8 and 10, the channel 79 between the frame uprights 9 and 13. The bearing assemblies 76, 77 are received through aligned openings in the channels 78, 79 and their flanges are made fast to the latter as by bolts.

The reduced diameter shaft end portions 74, 75 are coaxial and of the same diameter; however, the axis of the larger diameter central portion 71 is offset from about inch to about A; inch, preferably of the order of about inch and is parallel to theaxis of the end to the frame structure, the orbit being nominally circular and of about V inch to about Mr inch, preferably about inch, diameter.

The reduced diameter shaft end portion 74 is longer than the other reduced portion 75 and projects beyond the profile of the right side frame to receive a pulley 81 fast on the shaft. The shaftof the electric motor 4 carries an adjustable diameter pulley 82 of the automatic spring biased type, a V-helt 83 being trained around the drive pulley 82 and the driven pulley 81. The motor 4 is mounted fast on a carriage or platform 84 formed with front and rear depending flanges 85, 86. 7 These flanges have aligned bushings in drill holes, the bushings being received on parallel slide rods 89 the front and rear ends of which are supported by angle members 88 fastened to the tops of supplemental cross members 87 of the machine frame. The base members 11, 12 of the frame include portions which extend rearwardly beyond the legs 8, 9, the supplemental cross members 87' being welded at their endsto such rearward extensions of the base members.

Extending through the frame structure from front to rear and beneath the carrier 2 is a rotatable adjusting rod 91 supported by and received through a hole drilled in an angle bracket 92 fast to the front leg 6 of the frame. The distal or rear end of the rod 91 is guided and freely rotatable in a hole through one of the mounts 88 and is threaded through a matched and suitably reinforced threaded hole in the depending flange 85 of the motor carriage 84. Axial movement of the adjusting rod 91 is prevented by collars 80 fast on the rod on opposite sides of the mounting member 88 through which the rod is guided. A hand wheel 93is secured on the front end of the rod 91 outside the supporting bracket 92; inside the bracket a helical coil compression spring 94 embraces the adjusting rod and is confined between a collar 98 loose on the rod and frictionally engaged against the rear face of'the bracket 92 and a collar 95 fast on the rod. Rotation of the shaft 91 in one direction, as to the right, by means of the hand wheel 93 acts to draw the motor carriage 84 forwardly on the slide rods 89 or to the right as viewed in FIGS. 4 and 5; such movement reduces the distance between the axes of the pulleys 81 and 82 so as to increase the effective diameter of the automatic pulley 82, the V-belt 83 being inextensible. In this Way the driving ratio is decreased and the speed of the eccentric shaft 30 is relatively increased. Rotation of the adjusting rod 91 in the reverse direction, as to the left, has the converse efiect, shifting the motor carriage 84 to the left as viewed in FIGS. 4 and 5, thereby increasing the distance between the pulleys 81, 82; this increase in pulley distance reduces the effective diameter of the automatic pulley 82, thereby increasing the driving ratio and relatively decreasing the rotational speed of the eccentric shaft 30. The belt tension is maintained by the automatic pulley 82 which has sheave plates movable axially relative to one another and normally yieldingly urged together so as to squeeze the V-belt and move toward maximum operating diameter. The compression spring 94 and related parts on the adjusting rod comprise a friction lock which holds the rod in adjusted position.

The adjustable air spring or supporting cushion 60 comprises vertically spaced top and bottom turned or cast metal end members 96, 97 connected by a flexible tubular 1 member 98 of suitably reinforced rubber or rubberized fabric. The connections of the tubular member 98 to the end members are air tight and the resistance to vertical or axial compression of the device can be varied by altering the internal air pressure. The upper end member 96 is bolted or otherwise secured to a channel member 99 which extends transversely across and is fast to the underside of the carrier 2. The lower end member 97 is boltedor otherwise suitably secured to and reacts against a supplemental cross member 101 of the frame structure. Air is supplied to and vented from the cushion 60 through a pipe or conduit 102 connected into the bottom end member 97. The proper inflation is that which provides a vertical force suflicient to balance the weight of the carrier, tub and load comprising the parts being furnished and any media used. Thus the carrier and load floats in space and vibrated in substantially true circular orbit by the positive eccentric action of the crankshaft 30. i

Air under pressure is supplied from a suitable source such as an automatic power driven compressed air system or a pressurized air storage tank or a manually operated pump actuated as desired. The air supply is connected to the air cushion through the conduit 102 with check, regulating and bleed valves 103, 104 and 105, respectively, interposed and in series. These valves are for convenience mounted on control panel 106 of the control box 5; the panel projects laterally at the front and from the right side of the machine frame, the connections to the valves and other instruments being made in the rear of the panel and concealed in and protected by a suitable casing or cover 107 made of sheet metal and mounted on the frame for facile removal and replacement in servicing and repairing the controls; the control panel 106 remains in place when the cover 107 is removed. Connected into the air line 102 on the air spring 60 side of the regulating valve 104 and also mounted on the panel 106 is a pressure gauge 108 to show the air pressure existing in the air spring.

By manipulating the adjusting handle of the conventional pressure regulator 104, starting at a low pressure setting, the operator is able to provide in the air spring 68 the desired air pressure necessary to support the carrier 2. In making the adjustment, the means for supplying air under pressure being connected to the inlet side of the check valve 103 as shown, the regulator valve is gradually opened While observing the pressure gauge 158; when the desired pressure is achieved, as indicated on the dial of the gauge 108, the regulator 104 is left with the knob in the position so reached and functions automatically to maintain such pressure, feeding into the system such additional air under pressure as may be needed to replace any loss due to leakage. The check valve 103 serves to trap the air in the system of the air spring 60 against loss due to drop in the pressure of the air supply or disconnection of the external air supply conduit. The bleed valve is mounted on the control panel 1% adjacent the air pressure gauge 108 and is provided with an operating button 110 handy to the operator and which is depressed to relase air from the air spring 60 as, for example, whenever it is desired to reduce the inflation pressure.

The electrical drive motor 4 is connected by its lead Wires 111 to a suitable source of electrical energy such as a commercial power system. The electrical connection is desirably wired through a standard switch relay electrical controller combination the switch element of which, indicated at 112 is mounted on the control panel 106; this switch control has a start button 114 which is'depressed to effect energization of the motor 4 and a stop button 115 which is depressed to deenergize the motor. Also connected in the electrical circuit controlling the motor 4 is a conventionaladjustable timing device 116 mounted on the control panel 106, the timer being adapted automatically to deenergize the system and stop the motor 4 after a predetermined time interval of operation. The timer 116 has a control handle 117 by means of which the timer can be set manually to provide any desired operating period within the adjustment limits of the time, such as a given number of minutes or a fractional part of an hour. The switch means 112 overrides the timer 116; that is, if the machine be in operation, depressing the stop button 115 deenergizes the motor 4 and the machine stops regardless of the setting of the time. However, depressing the start button 114 onergizes the motor and sets the machine in operation only when the time is set to measure a time interval or is placed in hold condition, the latter shorting out the timer. Thus, when the start button 114 is depressed with the timer 116 in hold position the machine starts and remains in operauntil the stop button 115 is depressed. To make a timed run, actuation of the knob 117 of the timer 116 conditions the latter for a giventime interval or setting, automatically places the timer 116 in monitoring relation to the motor control relay or switch so that, after starting the machine by the start button and after the lapse of the time interval for which the timer is set, the timer automatically deenergizes the motor. 7

A tachometer or similar indicating device is provided to show the rotational speed of the eccentric shaft 30. One suitable generator type tachometer device for such-purpose comprises an element 118 mounted on the shaft 30 and an element 11% mounted on the control panel 106. The element 118 includes a part which is stationary and another part which rotates with the shaft. The relative rotation of the parts generates an electrical current which is translated into revolutions per minute shown by the dial of the element 119 on the control panel. By rotating the hand wheel 93 to shift the motor 4 on the slide bars 89 and thereby alter the pulley drive ratio, as described above, the operator is able to increase or decrease the rotary speed of the eccentric shaft 30 to the desired value. To use the vibratory machine of the present invention in finishing articles such as parts, castings or machinings of metal or plastic materials, a quantity or mass M comprising the articles, with or without an abrading medium such as particles or granite, aluminum oxide or the like, is charged into the compartment provided by the tub 3. The quantity charged may by any amount less than the maximum depthwhich is that required to fill the tub; the amount normally charged is preferably less than A, usually not more than from about /2 to about the volumetric capacity of the tub. To facilitate loading and unloading, the tub 3 is removed from the carrier 2 after first backing off the hand screw 41 to release the clamping bar 33. The closure panel or lid 48 is readilyremoved by backing off the hand screw 51. The loading may, of course, be achieved With the tub 3 mounted in the carrier 2, the closure panel'48 being removed and the mass M chargedinto the tub while the latter is "in place in the carrier pocket 20.

The abrasive media may also be other articles or any of the well known particulate materials used for the purpose. Water or other liquid medium is added; the tub is secured in the carrier by wedging it in the angle of the carrier pocket provided by the rear and bottom walls of the latter, and the motor 4 constituting the power means is energized to drive the eccentric shaft 30 and thereby impart the desired positive orbital movement to the mass M.

The motor 4 rotates in the direction of arrow 121, FIG. 3. Thus the eccentric shaft 30 is driven counterclockwise as viewed in FIGS. 3 and 8, clockwise as viewed in FIG. 6. Before starting the motor to set the machine in operation, the-air spring 60 is inflated to that pressure which causes it to exert a vertical force on the carrier 2 substantially equivalent to the combined weight of the carrier, tub and mass of the material to be treated. Such lifting force balances the weight of the mass to be orbited; the load thus is made to float soas to minimize the energy required to be supplied through the shaft 30 in the finishing process. Since the weight of the carrier and the tub are known, the operator need only determine the weight of the charge M, using conventional weighing procedures. The vertical force exerted by the air spring 60 for different inflation pressures is calculated or determined empirically; a chart or table is then prepared, giving the various inflation pressures to be used in the air spring 60 for different weights of the charge M.

When the machine is in operation with the tub 3 containing the work charge M, which charge also may include a quantity of water or other liquid to impart fluidity thereto, and with the eccentric shaft 30 rotating in the direction of the arrow 122 in FIG. 8, the charge M moves as a mass in a small substantially circular orbit; the orbital motion of the carrier and tub assembly as produced by the rapidly rotating'eccentric shaft 30 causes the individual 7 particles in the mass also to described small orbital paths posed at approximately a 45 angle to the horizontal.

Thus center of gravity 123 of; the charge mass M is displaced to the right, as viewed in FIG. 8 from what would be its normal position underthe center of the tub if the particles were to have a horizontal surface and be evenly distributed in the tub.

It is apparent from a consideration of FIG. 8 that both the lifting force exerted by the air spring 60 and the positive orbit producing driving forces exerted by the eccentric shaft 31) are applied to the carrier 2 at points that are relatively close to the center of gravity 123 of the mass M. Because of the specialized triangular geometry of the carrier 2, its relatively tall tapered side panels 21, 22 which place the distal ground attaching point, represented by the pin 67, remotely from the mass center of gravity 123, and which make the upper portions of the carrier relatively light in weight, there is achieved the result that center of gravity 125 of the carrier and center of gravity 126 of the combined carrier 2, tub 3 and mass M are also relatively close to the axis of the eccentric shaft 30 and to point 127 where the vertical force of the air spring 60 is applied to the carrier assembly. .The stabilizing link means 62 is spaced a vertical distance above the axis of the eccentric shaft means 30 which is several times the spacing ofthe center of gravity 126 above such axis. In the arrangement shown, wherein the height h of the distal anchorage point 67 of the stabilizing means above the axis of the eccentric shaft 30 is approximately 48 inches, the distance 0!, representing the-vertical height of the combined center of gravity 126 above the shaft axis, preferably is less than about A the distance h, being, in the example iven, approximately 7 inches or about the distance h. The point 127 atwhich the vertical or lifting force is applied to the carrier by the'air cushion 60 is relatively close as measured horizontally (distance ,1) in FIG. 8) to the vertical projection of the eccentric shaft 30; preferably such horizontal distance is less than half the vertical distance h from theshaft to the upper anchorage point 67. In the example given, the horizontal distance p is about 12 inches or A; the height h of the distal anchorage point 67 above the shaft axis. 7 .A line 131fro1n the force application point 127 to the axis of the anchorage pin 67 and a line 132 from the latter to the axis of the eccentric shaft 30 defines a small acute angle a within-which are included the center of gravity 123 of the mass M, the center of gravity 125 of the carrier assembly and the center of gravity 126 of the combined carrier assembly and the mass M. By this arrangement 9 the loads imposed on the pivot pins 66, 67 of the connecting link 62 and the resultant wear, are minimized. The vertical projections of the several centers of gravity 123, 125 and 126 lie between the vertical projections of the pressure applying point 127 and the axis of the eccentric shaft 30.

The eccentric weight 31 is so positioned on the shaft 30 that, with respect to the direction of rotation,; its radial axis, represented by the line 136, leads or is in advance of the radial axis of the eccentric portion 71 of'the shaft, represented by the line 135, by an obtuse angle b. Such lead angle is from about 100 to about 170 preferably from about 125 to about 145; in the embodiment shown the angle b is about 135. Relative to the rotational direction of the shaft 30 the weight 31 is thus retarded from a symmetrical position diametrically opposite the high point of the eccentric shaft portion 71. Such nonsymmetrical positioning of the balancing weight 31, in conjunction with the lifting force exerted on the carrier assembly at the point 127 by the air spring 60 results'in smooth orbital motion of the tub 3 and its contents. Each particle of the mass M describes a substantially symmetrical oval or elliptical path corresponding to the throw of the eccentric shaft portion 71. The particles of the mass also migrate in a general turning over or tumbling motion of the entire mass.

A closed tub or receptacle such as the illustrated tub 3 with its closure '48 has a limited volumetric capacity and therefore automatically limits the mass or charge M to a predetermined maximum depth which, in the presenter:- ample, is about 12 inches, such being the vertical height dimension k of the tub interior or compartment. In order to concentrate the load adjacent the drive shaft 30, the tub compartment height k is kept to a practical minimum; the vertical height h of the carrier-frame interconnection point 67 above the shaft 30 being at least several times greater than, that is, more than twice said tub compartment height, the latter representing the maximum depth of the loose mass M. The 4 to 1 height ratio shown adequately achieves thedesired separation of the mass from the interconnection point without exceeding practical height limitations in the frame 1.

The finisher of the present invention is thus characterized by its stabilizing interconnection of the carrier 2 and the framel at the pivot or link point comprising the pin 67 which is spaced from the rotational axis of the eccentric actuating shaft 30 a distance several times greater than the tub height and also several times the horizontal distance between such shaft axis and the point of application of the vertical or lifting force component provided by the air spring 60.

During operation the eccentric weight 31 balances the radial loads imposed on the shaft means by the reaction of the mass M and therefore it is desirable for the Weight to be located on the shaft between the axial limits of the projection of the mass M on such shaft, preferably midway between such limits, this being anothercharacterizing features of the invention.

Compactness and improved operating results are achieved by locating the actuating shaft wholly below a plane through the center of the tub 3 and laterally beyond the vertical projection of the tub compartment. There is, in effect, three point suspension of the carrier, being the link connecting point 67, the vertical lifting force point .127 and the point represented by the axis of the eccentric shaft 30. The carrier is restricted to oscillatory arcuate motion at the link point, is constrained to positive circular orbital movement at the shaft point, and has yieldingly resisted or damped universal movement combined with lift at the force point.

In positioning the air cushion 60, it is so located that its vertical force component is close to the center of gravity 123 of the working mass M and also to the combined center of gravity 126; such force component acts along a line passing through the mass M and closer to both the 10 mass center of gravity 123 and the combined center of gravity 126 than are the vertical projections of the shaft 30 on the horizontal planes containing such gravity centers.

A rotational speed of from about 500 to about 2500 revolutions per minute is used, depending in the character and rate of abrasive action'desired and the hardness and geometry of the articles being finished. The slower the speed, the less violent and severe is the abrasive action; hard, bulky, thick sectioned articles accept higher speed orbital movement without being subjected to-objectionable abrasive action than do soft thin, or intricate articles. Preferably, trial runs are made with each new variety of articles to determine abrasion resistance, acceptable media, water or liquid needed and time of operation.

In accordance with the patent statutes the principles of the present inventionmay be utilized in various ways, numerous modifications and alterations being contemplated, substitution of parts and changes in construction being restorted to as desired, it being understood that the embodiment shown in the drawings and described above are given merely for purposes of explanation and illustration without intending tolimit the scope of the claims to the specific details disclosed.

What I claim and desire to secure by Letters Patent of the United States is:

1. A vibratory finisher comprising a frame structure having spaced side members,

a carrier disposed between the side members,

shaft means journaled in the carrier and in the side members for rotationabout a substantially horizontal axis,

eccentric means on said shaft means and adapted upon rotation of the shaft means to actuate the carrier and impart orbital movement to the carrier relative to the frame structure,

resilient means reacting against the frame structure and exerting a vertical force component on the carrier, stabilizing means interconnecting the frame structure and a point of the carrier spaced vertically from said axis, said stabilizing means permitting oscillating movement of the carrier point relative to the frame structure,

" i said carrier having meansproviding a compartment for receiving and holding a predetermined maximum depth of a loose mass of articles to be finished and abrading media,

said interconnected carrier point being spaced from 'said axis a distance several times greater than said maximum depth of the loose mass,

and power means having a driving connection with said shaft means to rotate the latter.

2. A vibratory finisher as defined in claim 1 in which the eccentric means comprises an element having a circularprofile the center of which is on an axis parallel to and displaced from the horizontal axis of the shaft means a distance of from about to about /a inch,

a bearing on the carrier embracing said element,

and an eccentric weight fast on the shaft means with its center of gravity angularly displaced from the center of the eccentric element.

3. A vibratory finisher as defined in claim 2 in which, during rotation of the shaft means,

a first radial plane containing both the horizontal axis and the center of gravity of the eccentric weight leads by more than about degrees and less than about degrees a second radial plane containing both saidhorizontal axis and the center of the eccentric element.

4. A vibratory fiinisher as defined in claim 1 in which the eccentric means comprises a weight fast on the shaft means, i

said weight having a center of gravity which,

during operation of the finisher,

leads and is angularly displaced from the center of the eccentric element more than 100 degrees and less than 170 degrees in the direction of rotation.

5. A vibratory finisher comprising:

a frame structure, i a

a carrier having means providing a compartment for receiving and holding a loose mass of articles to be finished and abrading media,

means mounting the carrier in the frame structure for vibratory movement,

said mounting means comprising resilient means reacting against the frame structure and adapted to exert a force on the carrier opposite and substantially equal to the combined weight of the carrier and thesaid mass, shaft means journaled in the carrier and in the frame structure for rotation about a substantially horizontal axis, eccentric means on said shaft means adapted upon rotation of the shaft means to actuate the carrier and impart orbital movement to the carrier relative to the frame structure, i means interconnecting the frame structure and a point of the carrier remote from said shaft axis and constraining said point of the carrier against orbital movement while permitting oscillating movement thereof relative to the frame structure, and power means having a driving connection with said shaft means to rotate the latter. a 6. A vibratory finisher as defined in claim 5 in which the interconnecting means is vertically spaced from and relative to the axis of the shaft.

7. A vibratory finisher as defined in claim 5 in which the interconnecting means comprises a link and pin means connecting spaced points of the link to each of said carrier and said frame structure. V

8. A vibratory finisher as defined inclaim 5 in which the resilient means comprises a compression spring located below and disposed to actalong a line substantially through the center of said compartment.

9. A vibratory finisher as defined in claim 5 in which the resilient means comprises an inflatable air spring and which includes control means adapted to admit air into and release air from said spring while the finisher is in continuous operation in adjusting said force to the combined weight. w a

It A vibratory finisher as defined in claim 5 in which the carrier includes bottom wall means and upright wall means angularly disposed relative to the bottom wall means and is formed with an open top pocket,

a tub adapted for easy insertion into and removal from said pocket through the open top,

the tub providing said compartment and having a top opening into the latter,

and means clamping thetub in the pocket of the carrier in the angle between the uprightwall means and the bottom 'wall means and in predetermined relative position. i

11. A vibratory finisher comprising a frame structure,

a carrier including means providing a compartment for receiving and holding a loose mass of articlesto be finished and abrading media to accomplish the finishing,

i2 resilient means reacting against the frame structure and exerting a .force component on the carrier along a vertical axis through the compartment; stabilizing means connectingthe carrier to the frame structure -,for;relative movement,

.said stabilizing means being spaced above the compartment a distance more than twice the height of the compartment,

and rotary eccentric means interconnecting the carrier and the frame structure and adapted to impart orbital movement to the carrier compartment and a received mass,

the rotational axis ofsaid eccentric means being he low the center andspaced horizontallybeyond the vertical-projection of the compartment.

12. -A vibratory finisher as defined in claim 11 in which during operation a vertical line through the center of gravity of the combined carrier and a normal received mass for which the finisher is designed is located intermediate and horizontally spaced from both the vertical axis of the force component of the resilient means and a vertical plane containing the axis of the eccentric means. i

13. In 'a'vibratory finisher as defined in claim 12 the horizontal'spacing of the center of gravity from the eccentric means being greater than its horizontal spacing from the axis of the resilient means. i

14. In a vibratory finisher as defined in claim 12 the stabilizing means and the center of gravity of the combined carrier and received mass during operation each being spaced above the axis of the eccentric means, and

i said last mentioned spacing of the stabilizing means v said wall elements each being flat and normal to the end Walls with all portions of the wall elements spaced inwardly fromthe peripheries of the end walls, 'and one of 'said wall elements being adapted to be readily rem'oved to provide an opening into the chamber'for charging and discharging articles into and from the'charnber and readily replaced as a closure for said opening.

. References Cited by the Examiner .UNITED STATES PATENTS 2,515,693 7/50 'Buhrer.

2,757,544 8/56 Becker. i 1

2,758,362 8/56 Benedict 51-164 X 2,997,813 V 8/61 Brandt 51-7 LESTER M. SWINGLE, Primary Examiner;

JOHN C. CHRISTIE, Examiner. 

11. A VIBRATORY FINISHER COMPRISING A FRAME STRUCTURE, A CARRIER INCLUDING MEANS PROVIDING A COMPARTMENT FOR RECEIVING AND HOLDING A LOOSE MASS OF ARTICLES TO BE FINISHED AND ABRADING MEDIA TO ACCOMPLISH THE FINISHING, RESILIENT MEANS REACTING AGAINST THE FRAME STRUCTURE AND EXERTING A FORCE COMPONENT ON THE CARRIER ALONG A VERTICAL AXIS THROUGH THE COMPARTMENT; STABILIZING MEANS CONNECTING THE CARRIER TO THE FRAME STRUCTURE FOR RELATIVE MOVEMENT, SAID STABILIZING MEANS BEING SPACED ABOVE THE COMPARTMENT OF DISTANCE MORE THAN TWICE THE HEIGHT OF THE COMPARTMENT, AND ROTARY ECCENTRIC MEANS INTERCONNECTING THE CARRIER AND THE FRAME STRUCTURE AND ADAPTED TO IMPART ORBITAL MOVEMENT TO THE CARRIER COMPARTMENT AND A RECEIVED MASS, THE ROTATIONAL AXIS OF SAID ECCENTRIC MEANS BEING BELOW THE CENTER AND SPACED HORIZONTALLY BEYOND THE VERTICAL PROJECTION OF THE COMPARTMENT. 